Add new -x XID option to /contrib/pg_resetxlog for future pg_upgrade use.

diff --git a/contrib/pg_resetxlog/README.pg_resetxlog b/contrib/pg_resetxlog/README.pg_resetxlog
index f9521ee0d63043ee7203696e0df0390a4f337c9a..943b2a1b0c1337b68540e8b4ec23e0a526647042 100644 (file)
--- a/contrib/pg_resetxlog/README.pg_resetxlog
+++ b/contrib/pg_resetxlog/README.pg_resetxlog
@@ -21,6 +21,9 @@ module pg_controldata and run it to be sure the DB state is SHUTDOWN).
 Then run pg_resetxlog, and finally install and start the new version of
 the database software.
 
+A tertiary purpose it its use by pg_upgrade to set the next transaction
+id in pg_control.
+
 To run the program, make sure your postmaster is not running, then
 (as the Postgres admin user) do
 

diff --git a/contrib/pg_resetxlog/pg_resetxlog.c b/contrib/pg_resetxlog/pg_resetxlog.c
index 554bc83939974bbb91d64b5e649c38138699f9cf..7889cdcf3333f5ec595fb95a98a83825b473a259 100644 (file)
--- a/contrib/pg_resetxlog/pg_resetxlog.c
+++ b/contrib/pg_resetxlog/pg_resetxlog.c
@@ -23,7 +23,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/contrib/pg_resetxlog/Attic/pg_resetxlog.c,v 1.10 2001/11/05 17:46:23 momjian Exp $
+ * $Header: /cvsroot/pgsql/contrib/pg_resetxlog/Attic/pg_resetxlog.c,v 1.11 2002/01/10 17:51:52 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -709,34 +709,39 @@ PrintControlValues(void)
  * Write out the new pg_control file.
  */
 static void
-RewriteControlFile(void)
+RewriteControlFile(TransactionId set_xid)
 {
    int         fd;
    char        buffer[BLCKSZ]; /* need not be aligned */
 
-   /*
-    * Adjust fields as needed to force an empty XLOG starting at the next
-    * available segment.
-    */
-   newXlogId = ControlFile.logId;
-   newXlogSeg = ControlFile.logSeg;
-   /* be sure we wrap around correctly at end of a logfile */
-   NextLogSeg(newXlogId, newXlogSeg);
-
-   ControlFile.checkPointCopy.redo.xlogid = newXlogId;
-   ControlFile.checkPointCopy.redo.xrecoff =
-       newXlogSeg * XLogSegSize + SizeOfXLogPHD;
-   ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
-   ControlFile.checkPointCopy.time = time(NULL);
-
-   ControlFile.state = DB_SHUTDOWNED;
-   ControlFile.time = time(NULL);
-   ControlFile.logId = newXlogId;
-   ControlFile.logSeg = newXlogSeg + 1;
-   ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
-   ControlFile.prevCheckPoint.xlogid = 0;
-   ControlFile.prevCheckPoint.xrecoff = 0;
-
+   if (set_xid == 0)
+   {
+       /*
+        * Adjust fields as needed to force an empty XLOG starting at the next
+        * available segment.
+        */
+       newXlogId = ControlFile.logId;
+       newXlogSeg = ControlFile.logSeg;
+       /* be sure we wrap around correctly at end of a logfile */
+       NextLogSeg(newXlogId, newXlogSeg);
+   
+       ControlFile.checkPointCopy.redo.xlogid = newXlogId;
+       ControlFile.checkPointCopy.redo.xrecoff =
+           newXlogSeg * XLogSegSize + SizeOfXLogPHD;
+       ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
+       ControlFile.checkPointCopy.time = time(NULL);
+   
+       ControlFile.state = DB_SHUTDOWNED;
+       ControlFile.time = time(NULL);
+       ControlFile.logId = newXlogId;
+       ControlFile.logSeg = newXlogSeg + 1;
+       ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
+       ControlFile.prevCheckPoint.xlogid = 0;
+       ControlFile.prevCheckPoint.xrecoff = 0;
+   }
+   else
+       ControlFile.checkPointCopy.nextXid = set_xid;
+   
    /* Contents are protected with a CRC */
    INIT_CRC64(ControlFile.crc);
    COMP_CRC64(ControlFile.crc,
@@ -926,9 +931,10 @@ WriteEmptyXLOG(void)
 static void
 usage(void)
 {
-   fprintf(stderr, "Usage: pg_resetxlog [-f] [-n] PGDataDirectory\n\n"
-           "  -f\tforce update to be done\n"
-           "  -n\tno update, just show extracted pg_control values (for testing)\n");
+   fprintf(stderr, "Usage: pg_resetxlog [-f] [-n] [-x xid] PGDataDirectory\n"
+           " -f\tforce update to be done\n"
+           " -n\tno update, just show extracted pg_control values (for testing)\n"
+           " -x XID\tset XID in pg_control\n");
    exit(1);
 }
 
@@ -939,6 +945,7 @@ main(int argc, char **argv)
    int         argn;
    bool        force = false;
    bool        noupdate = false;
+   TransactionId set_xid = 0;
    int         fd;
    char        path[MAXPGPATH];
 
@@ -950,6 +957,18 @@ main(int argc, char **argv)
            force = true;
        else if (strcmp(argv[argn], "-n") == 0)
            noupdate = true;
+       else if (strcmp(argv[argn], "-x") == 0)
+       {
+           argn++;
+           if (argn == argc)
+               usage();
+           set_xid = strtoul(argv[argn], NULL, 0);
+           if (set_xid == 0)
+           {
+               fprintf(stderr, "XID can not be 0.");
+               exit(1);
+           }
+       }
        else
            usage();
    }
@@ -992,6 +1011,20 @@ main(int argc, char **argv)
    if (!ReadControlFile())
        GuessControlValues();
 
+   /*
+    * Set XID in pg_control and exit
+    */
+   if (set_xid)
+   {
+       if (guessed)
+       {
+           printf("\npg_control appears corrupt.  Can not update XID.\n");
+           exit(1);
+       }
+       RewriteControlFile(set_xid);
+       exit(0);
+   }
+
    /*
     * If we had to guess anything, and -f was not given, just print the
     * guessed values and exit.  Also print if -n is given.
@@ -1018,7 +1051,7 @@ main(int argc, char **argv)
    /*
     * Else, do the dirty deed.
     */
-   RewriteControlFile();
+   RewriteControlFile(0);
    KillExistingXLOG();
    WriteEmptyXLOG();